Apparatus for supplying a drying medium



Aug. 28, 1923. 1,466.443

C. E. BRADLEY ET AL APPARATUS FOR SUPPLYING A DRYING MEDIUM Original Filed Dec. 7. 1921 ijwwemtow CHARLES E.BRADLEY 6:. Jo SEPH G. COFHN UNWE STTS E. BRADLEY, OF MONTCLAIR, NEW JERSEY, AND JOSEPH G. COFFIN, 01F

. TION OF NEW JERSEY.

PSTEAD, NEW YORK, ASSIGNOBS T GENERAL RUBBER COMPANY, A CORPO- APPABATUB FOR .SUPPLYING A DRYING MEDIUM Original application filed December 7, 1921, Serial Ho. 520,505. Divided and this application filed,

April 3, 1922.

To all whom it may concern:

Be it known that we, CHAnLEs EL BRAD- LEY and JOSEPH G. COFFIN, both citizens of the United States, and residing at Montclair, in the count of Essex and State of New Jersey, and empstead, Long Island, in the county of Nassau and State of New York, respectively, have invented a, certain new and useful Apparatus for Su plying a Drying Medium, of which the 0 owing 1s a full, clear, and exact description.

This imention relates to an apparatus for supplying a drying medium, more particularly to means for supplying a suitable drying medium to a latex drying apparatus,

such as that disclosed in our copending application, Serial No. 520,505,'filed December -7, 1921, since become Patent No. 1,428,52t5, granted September 12, 1922, of which this 2 application is a division,

pparatus for supplying a heated drying medium may be divided broadly mtotwo classes. First, those in which the drying medium is indirectly heated by transferring heat through an intervening wall from a heating element or medium. Second, those in whlch the drying medium is direccty heated by mixing it with combustion pr ucts, or in which heated combustion products alone are used as the drying medlum. Apparatus of the first type is not economical in that where it is desired to heat the drying medium to a relatively high temperature it is impossible to prevent large heat losses, as in practice all of the heat cannot be transferred from the heating medlum to the drying medium. In addition, in certain cases it is desirable to add the combustion products used for the heating to the drying medium by reason of the improved efiect obtained upon the material dried, as in our copending application above mentioned. Apparatus of the second type is also not economical, because as ordinarily constructed there is also a considerable loss of heat in these. In devices'of the second type combustion is usually carried on at the ordinary furnace pressures, thereby allowin a considerable escape of heat through t e usual so furnace openings.

An object of our invention is to provide an improved means for supplying a heated drying medium.

Serial No. 549,360.

Another object is to provide a means for supplylng a heated drying medium in which heat losses are substantially eliminated.

Still another object is to provide an improved means for directly heating air or other gas by admixture of combustion products therewith.

A further object is to provide means, operating under reduced pressure, for supplymg a regulable mixture of heated air and combustion products.

Fora detailed disclosure of the invention reference is had to the-accompanying specification and drawing, in which latter:

Fig. 1 is a horizontal section through the apparatus;

Fig. 2 is a vertical longitudinal section through the furnace proper, or combustion chamber. I

Referring to the drawings, the furnace 1 comprises a combustion chamber 2, which is preferably elongated, and provided at one end with an oil burner 3 of any suitable type to which are connected the respective oil and air supply pipes 4: and 5. Any suitable means 6 for admitting air for combustion around the burner may beused. At the bottom the furnace is equipped with a suitable damper 7 for admitting additional air for combustion, which air passes inwardly through longitudinal passages 8 formed by the loosely placed fire brick 9, and is discharged upwardly into the combustion chamber through the transverse openings 10 formed by the fire brick 11. Adjacent the opposite end of the combustion chamber is an exhaust passage 12 which communicates with a mixing chamber 13 .at an interme diate'point in the latter, preferably at about its middle portion.

The mixing chamber in the present instance is formed as a straight relatively extended passage, and a screen 14 is removably disposed therein across the inlet of the exhaust passage 12 to the chamber, which screen is supported in position by the frame 15. This screen may be made of nichrome metal or any other suitable heat resistant material. At one end of the mixing chamber is an air inlet governed by the gate 16, while at the other end is an exhaust open- ,ing controlled by the gate 17, which opening is in connection with the casing 18 of a,

so in themining chamber 13 a suction fan. This fan may driven in any desired manner, as by the belt 19. Leading from the fan casing 18 is a conduit 20 for conducting the mixed air and combustion e products to the drying apparatus.

lln operation the gate 17 is first closed, thegate 16 opened, and the oil burner 3 then started. This allows the combustion products to exhaust directly into the open to air until such time as the furnace has been properly heated up. The ate 1'? is then opened and the fan starte thereby causing an inflow of air to the mixing chamber through the aid inlet, and .at the same time 15 exhausting the combustion products from ture of combustion products and air may be obtained, and the temperature of the mixture properly regulated. The purpose of the screen 14L is to remove any solid particles in the combustion products as they pass into the mixing chamber, particularly particles which may be drawn into the furnace through the various air inlets by reason of the suction. It will be noted that the screen is so disposed that after the air begins to flow in through the gate 16 such air assists in cooling the screen and thereby lengthens its life. Moreover, by reason of its disposition it may be readily removed for repair or inspection. The fire brick pieces 9* and 11 are preferably loosely arranged in the furnace so that their disposition may be altered, as desired. lit will be seen that during the operation of the device combustion takes place iii the chamber 2 under reduced pressure, and since air is being drawn in at all the inlets there are no heat losses. whatever at such inlets, and the furnace operates at a maximum eflici'ency.

Hence small cracks or leaks which would .ordinarily be objectionable do not in any way impair the operation of the furnace. By disposing the mixin chamber 13 at substantially a right ang e to the exhaust passage 12 the combustion products are given a shar bend as they enter the mixing chamber an more quickly mixed with the air. This also eliminates the destructive action of radiant heat from the combustion chamber on the fan in casing 18. Moreover, for the particular purpose for which the apparatus is designed, namely to furnish a heated medium for drying rubber latex, the use of combustion products in the-drylng medium is in some cases-desirable It also lessens the percentage of free oxygen in the drying medium, and thereby lessens I the oxidizing efilect of such medium on the rubber during the drying process. it is evident that liquid,gaseous, or even solid fuel may be utilized in the furnace proper, it is preferable to use liquid or gaseous fuel, owing to the absence under roper working conditions of an solid comustion products which it woul be dificult to eliminate from the drying medium. As it is desired that there shall be complete combustion in the combustion chamber, it should be made of a length sullicient to obtain this result. a

While a specific embodiment of the invention has been disclosed, it is obvious that chan es may be made therein and it is not desired to limit the invention otherwise than as set forth in the appended claims.

Having thus described our invention,

While what we claim and desire to protect by Letters Patent is:

1. An apparatus for supplying a drying medium comprising a combustion chamber, a mixing chamber, a passage leading from adjacent the. end of the combustion chamher to an intermediate point of the mixing chamber, an air inlet at one end of the mixing chamber, and means at the other end thereof for exhausting mixed air and combustion products.

2. An apparatus for supplying a drying medium comprising a combustion chamber,- regulable means for supplying air thereto, a mixin chamber, a connection from-said combustion chamber to an intermediate point of said mixin chamber, an air inlet at one end of the mixing chamber, an outlet at the other end, controlling means for said inlet and outlet, and a suction device connected to said outlet.

3. An apparatus for supplying a drying medium comprising a combustionfcham 1', means at one end thereof for admitting fluid fuel, regulable means for admitting air, an outlet adjacent the other end of the chamber, a mixing chamber connected thereto, a regulable air inlet to said mixing ch :1 it her atone end, an outlet at the other end, and a suction device at said outlet. i

d. An apparatus for supplying a drying medium comprising a combustion chamber, means at one end thereof for admitting fluid fuel, regulable means for itting air thereto, an outlet at the other end, a

"mixing chamber connected at an intermediate point to said outlet, an air inlet at one end of said mixing chamber, a regulable outlet at the other end thereof, and suction means for conducting away the mixed air andcombustion products.

5. An apparatus for supplying a ng medium comprising a combustion chamber,

regulahle means at, one end thereof for ieo burning fluid fuel, a mixing chamber, a passage leading from the opposite end of said combustion chamber to an intermediate point of said mixing chamber, a screen disposed in said mixing chamber at the inlet of said passage thereto, an air inlet at one end of the mixing chamber, an outlet at the other end thereof, and suction means at said outlet for exhausting and conducting away the mixed combustion products and air.

6. An apparatus for supplying a drying medium comprising an extended combustion chamber, an extended mixing chamber, an exhaust passage leading from the combustion chamber to the mixing chamber, oppositely disposed openings in the mixing chamber, controlling means for said openings, a discharge passage connected to one of said openings, and a suction device disposed in said passage.

7. An apparatus for supplying a drying medium comprising an extended combustion chamber, an extended mixing chamber, a passage leading from the combustion cham her to the mixing chamber, a screen disposed in the mixing chamber over the outlet of said passage, a controlled inlet and outlet for the mixing chamber, and a suction device connected to said outlet.

8. An apparatus for supplying a drying medium comprising an extended combustion chamber, an extended mixing chamber having a controlled air inlet at one end and an outlet at the other end, a passage leading from said combustion chamber into said mixing chamber between said inlet and outlet, a screen removably disposed in the mixing chamber over the outlet of said passage, and means connected to the outlet of the mixing chamber for exhausting, additionally mixing and conducting away the combustion products and air.

9. An apparatus for supplying a drying medium comprising a combustion chamber, means for maintaining combustion therein under reduced pressure and for conducting away the combustion products, controllable means for admitting air to the combustion products, and means for at will changing the direction of flow of said combustion products.

10. An apparatus for supplying a drying medium comprising a combustion chamber, means for maintaining combustion therein under reduced pressure and for conducting away the combustion products, and controllable means for at will admitting air to the combustion products or diverting the combustion products through said air admission means.

Signed at New York, in the county of 

